It is already known that the number of compounds represented by the general formula (II) ##STR1##
wherein Ar represents phenyl or substituted phenyl, R represents H or methyl, n is 2 or 3 and Ar.sub.1 represents substituted phenyl, possess calcium channel blocking activity. From these substances Verapamil (generic name, Merck index, 11th Edition, 9851) represented by the general formula (II), wherein Ar and Ar.sub.1 represent 3,4-dimethoxyphenyl, R represents methyl, n is 2, has effective calcium channel blocking activity and has been clinically used for the treatment of ischemic heart disease, arrhythmias and hypertension. In an advanced phase of clinical testing is Mepamil (proposed generic name) represented by the general formula (II), wherein Ar represents 2-methylphenyl, R represents methyl, n is 2 and Ar.sub.1 represents 3,4-dimethoxyphenyl. The latter compound exhibits, compared to Verapamil, lower negative inotropic activity (Blaha L. et al. CS Patent 258534).
It is already known from the literature (Mitani K. et al.: Chem. Pharm. Bull., 36, 367 (1988), Mitani K. et al.: Chem. Pharm. Bull., 36, 373 (1988)), that compounds of general formula (II), wherein Ar represents phenyl, alkoxyphenyl, dialkoxyphenyl or trialkoxyphenyl group, R represents H or methyl, and Ar.sub.1 represents substituted phenyloxy group exhibit calcium channel blocking and .alpha.-adrenergic blocking activity.
Furthermore, it is known, that some derivatives of 2-aminomethyl-2,3-dihydro-1,4-benzodioxine, e.g. Piperoxan (generic name, Merck index, 11th Edition, 7448) block the .alpha.-adrenergic receptors in a competitive manner and that the activity of the S-enantiomer is more pronounced, than that of the R-enantiomer (Nelson, L. N., Wennerstrom, J. E.: J. Med. Chem., 20, 880 (1977)).
According to our knowledge, derivatives of 2-aminomethyl-2,3-dihydro-1,4-benzodioxine exhibiting except of the .alpha.-adrenergic blocking activity also calcium channel blocking activity have not been described yet.